Gardener's World - Monty's Sweet Pea Experiment

Hello - I coped Monty's Sweet Pea experiment by planting some seeds prior to Christmas to see if they prove to be better plants than those to be planted later....I forgot to note when 'later' is! Can anybody advise?

The first batch are going strong and I have nipped the tops off so they are bushing up nicely. The only downside is that some of the seeds didn't germinate. Did anyone else have a go and if so how are you getting on?

Personally I favour after Christmas. I've had good results from spring sowings. It saves you the hassle of looking after them over winter. Giving them nice fertile soil (dig in lots of organic matter) and watering a lot both help enormously.

Also, the earlier you sow, the earlier they'll flower and ultimately die. Ideally you'd probably sow some early and some late, to have sweet peas for as long as possible.